Self-locking coin receptacles are used with telephone paystations to facilitate coin collection. Most self-locking coin receptacles of the major telephone paystation manufacturers (e.g., AT&T, Nortel, Lucent, BellSouth, Pacific Bell, U.S. West, Ameritech, Bell Atlantic and GTE) are similar. The basic operation of self-locking coin receptacles is described in detail in U.S. Pat. No. 3,837,566 to McGough, incorporated herein by reference.
A self-locking coin receptacle includes a receptacle and a self-locking aperture cover. The self-locking aperture cover has mounted within it a shutter plate and a shutter control arm that extends externally of the cover to engage a bracket in the vault within the paystation. Sliding the receptacle into the vault of a paystation moves the control arm which opens a shutter covering an aperture within the cover. Coins traveling down a coin track pass through the open aperture to the receptacle. When the receptacle is removed from the paystation, a biasing member moves the shutter plate so it closes the aperture to the receptacle. The cover includes a latching mechanism that blocks movement of the shutter plate so the aperture remains closed and easy access to the contents of the receptacle is thereby denied.
Self-locking receptacles were developed so the receptacle could be removed from a paystation and transported to a safe collection facility rather than having the employee empty the receptacle at the paystation. Accumulation of money from receptacles at multiple paystations results in sums of money that may entice robbery attempts and present risks to the service personnel. The incentive for robbery declines if a thief has to defeat a locking mechanism to access the contents of each receptacle a service person may possess. Also, the self-locking covers help deter employees from taking a portion of the money contained within the receptacles of paystations on a service route.
Attempts have been made to design self-locking coin receptacles that are substantially tamper proof or that indicate whether tampering or tampering efforts have occurred. For example, U.S. Pat. Nos. 4,194,775 to Shea, 5,515,030 to Citron, et al. and 4,204,709 to Shea disclose systems that improve the locking engagement between a self-locking cover and its coin receptacle. However, telephone paystation companies have discovered that some self-locking covers can be forced open and the contents of the receptacle accessed without leaving readily noticeable signs of tampering. Thus, service personnel may be able to remove some or all of the contents of a coin receptacle without providing any indication of receptacle tampering.